Which of these is the correct form of the solution for y′=ky(M−y)y' = ky(M-y)y′=ky(M−y)?
y(t)=Ae−Mkty(t) = Ae^{-Mkt}y(t)=Ae−Mkt
y(t)=M(1−e−kt)y(t) = M(1-e^{-kt})y(t)=M(1−e−kt)
y(t)=M1+AeMkty(t) = \frac{M}{1 + Ae^{Mkt}}y(t)=1+AeMktM
y(t)=M1+Ae−Mkty(t) = \frac{M}{1 + Ae^{-Mkt}}y(t)=1+Ae−MktM